The roof structures of the buildings typically comprise load bearing roof beams as well as a separate thermal insulation material layer and air and vapour barrier layers. The load bearing roof beams can be for example timber, concrete or steel. The existing structures are often labour-consuming with many working phases.
In case of fire, the inner load bearing structure of the roof structures is typically immediately exposed to a high temperature and thus its strength begins to weaken quickly.
Furthermore, the moisture condensing in the roof structures or the rain water possibly entering the structures can cause problems, for example waterlogging of the thermal insulation material and thus damage of the structures.